Institute an operational mouse screen, establish its reliability by testing two known iron chelators, and initiate an inventory of test compounds to ensure continuity in performing bioassays. The overall objective is to determine the efficacy of approximately 80 potential iron chelators in the first year of performance. In addition, some knowledge of acute toxicity of each compound will be documented. The screen will essentially encompass: drug formulation; obtaining some acute toxicity data; hypertransfusion; a seven day I.P. treatment interval with relevant dosages; collection of tissues and excreta; and iron analysis and statistical evaluation. Multiple testing with comparison of activities to a standard clinical reference chelator will make the screens definitive, timely, and cost-effective.